1. Field of the Invention
This invention is directed to antiwear/extreme pressure additives comprising a mixture of an organic acid ester and a phosphosulfurized oil.
2. Discussion of the Prior Art
Lubricants are subject to heavy stresses that can affect their antiwear and loading-carrying ability and lubricants used in metal working, heavy industrial machinery and the like are often subject to high temperatures and pressures which affect their extreme pressure properties. Prior art lubricant compositions have not always been adapted to withstand these extreme conditions. Thus there is a constant need and effort to discover classes of compounds that will aid in retaining or, preferably, in improving these important properties.
U.S. Pat. No. 3,278,432 discloses the use of alkaline earth metal salts of C.sub.1 -C.sub.4 carboxylic acids and sulfur containing material such as sulfur, hydrocarbyl sulfides and sulfurized oils and fats as being useful in E.P. additive formulations and U.S. Pat. No. 4,028,259 discloses oil-soluble, phosphorus and sulfur containing oxidized oil reaction products as lube oil additives.